On 24.05.2017 00:03, John Campbell wrote: > Cool... > > Though the real key is that the mainframe is designed for something at or > beyond five 9s (99.999%) uptime. > > [HUMOR] > Heard from a Tandem guy: "Your application, as critical as it is, is on a > nine 5s (55.5555555%) platform." > [/HUMOR]
Mostly you trade complexity in hardware with complexity in software. Mainframes do not scale limitless either, so you trade being able to grow your service by adding hardware with doing it within the boundaries of a sysplex. Your first statement is also imprecise. It's designed for five 9s excluding scheduled downtime. If you use the fact that hardware is unrealiable (after subtracting your grossly overstated unreliability) to your advantage, you end up with a system where any component can fail and it doesn't matter. You win. Again, it then comes down to the trade-off question if you're willing to pay for the smart software and the smart brains to maintain it rather than paying IBM to provide service for the mainframe. Kind regards Philipp Kern ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
